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1.
目的了解肺炎克雷伯菌染色体、质粒介导喹诺酮类耐药基因gyrA、qnrA、qnrB、qnrS、aac(6′)-Ⅰb-Cr和qepA基因的流行情况。方法采用PCR法对20株肺炎克雷伯菌进行gyrA、qnrA、qnrB、qnrS、aac(6′)-Ⅰb-Cr和qepA基因检测,稀释法检测20种抗菌药物的体外抗菌活性,PCR扩增产物经纯化后测序并进行序列分析。结果20株肺炎克雷伯菌均存在突变,aac(6′)-Ⅰb和qnrS基因各检出1株,经比对分别为aac(6′)-Ⅰb-Cr和qnrS1。结论老年患者产超广谱β-内酰胺酶肺炎克雷伯菌对环丙沙星耐药主要为gyrA基因突变所致,但也有aac(6′)-Ⅰb-Cr和qnrS的因素。  相似文献   

2.
目的研究肺炎克雷伯菌(KPN)烧伤分离株的喹诺酮类耐药机制。方法测定1株分离自烧伤科患者血液的肺炎克雷伯菌对3种喹诺酮类药物的敏感性,采用PCR方法进行6种喹诺酮类耐药基因[aac(6′)-Ⅰb、qnrA、qnrB、qnrS、qepA和gyrA]检测,并对aac(6′)-Ⅰb和gyrA PCR阳性产物进行基因测序并作BLASTx比对分析。结果该菌株对诺氟沙星和环丙沙星耐药,对左氧氟沙星敏感;PCR检测发现该菌株同时携带qnrB、qnrS及aac(6′)-Ⅰb,对aac(6′)-Ⅰb基因测序证实为aac(6′)-Ⅰb-cr突变体,对gyrA基因测序证实其83位丝氨酸(S)被异亮氨酸(I)所替代,并有65位丝氨酸(S)发生同义突变,作为新亚型已登录美国NCBI基因库(登录号为GQ422758)。结论首次发现一同时携带qnrB、qnrS及aac(6′)-Ⅰb-cr共3种质粒介导的喹诺酮类耐药基因肺炎克雷伯菌烧伤分离株,同时其gyrA基因66、83位氨基酸均有突变,为一新亚型;这对临床上预防控制多药耐药KPN在烧伤科的流行提出了更高的要求。  相似文献   

3.
目的分析广州地区大肠埃希菌对喹诺酮类等12种抗菌药物耐药性,探讨qnr、qepA、aac-(6′)-Ib-cr质粒基因流行状况以及与耐药的关系。方法收集广州市两所三甲医院临床分离大肠埃希菌103株,采用纸片扩散法进行药敏试验,采用PCR技术检测大肠埃希菌中qnr(qnrA、qnrB、qnrS)、aac-(6′)-Ib-cr和qepA质粒基因,并对PCR产物进行DNA测序分析。结果 103株大肠埃希菌对喹诺酮类抗菌药物的耐药率均>50.0%,20株菌检出阳性基因qnrB、qnrS、aac(6′)-Ib-cr的阳性率分别为9.7%、7.8%、10.7%,有8株菌同时携带≥2种质粒基因,这8株菌对喹诺酮类药物全部耐药,同时合并其他类抗菌药物耐药,其中52号菌同时携带3种基因[qnrB、qnrS、aac-(6′)-Ⅰb-cr],对6类抗菌药物全部耐药,12株菌检出单个质粒基因,其中4株对喹诺酮类敏感。结论广州市大肠埃希菌对喹诺酮类抗菌药物耐药率居高不下;药敏谱呈多样化,多药耐药株比例高;菌株中存在qnrB、qnrS、aac-(6′)-Ⅰb-cr的流行,并呈现出两种或多种耐药基因共存于同一株细菌的特征;质粒介导的喹诺酮耐药基因数量与耐药种类数量呈正相关。  相似文献   

4.
目的调查多药耐药肺炎克雷伯菌中喹诺酮类耐药相关基因的存在与变异状况。方法收集绍兴市人民医院2007年10月-2009年6月住院患者标本中分离的多药耐药肺炎克雷伯菌共20株,采用聚合酶链反应及序列分析的方法分析1种染色体介导的喹诺酮类耐药相关基因(gyrA基因)和5种质粒介导的喹诺酮类耐药相关基因〔qnrA、qnrB、qnrS、aac(6′)-Ⅰb、qepA基因〕。结果 gyrA基因83位密码子17株菌(85.0%)有突变,87位密码子7株菌(35.0%)有突变,各分为4种突变方式;SX007株存在同义突变的gyrA基因新亚型,SX001、002、003、006、017株同时存在有义突变和同义突变的gyrA基因新亚型;另检出aac(6′)-Ⅰb-Cr基因2株(10.0%),qnrB基因1株(5.0%),qnrS基因4株(20.0%);qnrA和qepA基因未检出。结论该组多药耐药肺炎克雷伯菌gyrA基因突变率高,这是喹诺酮类耐药的主要原因,其他耐药基因阳性率比较低。  相似文献   

5.
目的 研究多药耐药肺炎克雷伯菌(MDRKP)氨基糖苷类药物耐药的遗传学背景.方法 收集2008年8月-2010年5月6所医院共47株肺炎克雷伯菌,采用聚合酶链反应(PCR)的方法分析15种氨基糖苷类修饰酶和6种16S rRNA甲基化酶基因.结果 该组肺炎克雷伯菌共检出4种氨基糖苷类修饰酶和1种16S rRNA甲基化酶基因,可分为16种阳性检出模式,并发现两株菌携带aac(6′)-Ⅰ b基因新亚型[aac(6′)-Ⅰ b-hz,美国GenBank登录号:JF901756];其他16种基因未检出.结论 携带氨基糖苷类修饰酶和16S rRNA甲基化酶基因,是该组肺炎克雷伯菌对氨基糖苷类药物耐药的主要原因,在多药耐药肺炎克雷伯菌中发现aac(6′)-Ⅰ b新亚型[aac(6′)-Ⅰ′ b-hz]为国内外首次报道.  相似文献   

6.
肠杆菌科细菌qnr耐药基因的流行现状及耐药分析   总被引:1,自引:0,他引:1  
目的了解质粒介导喹诺酮类耐药基因qnrA、qnrB、qnrS在临床分离大肠埃希菌、肺炎克雷伯菌、阴沟肠杆菌、鲍氏不动杆菌中的流行情况及其耐药特征。方法收集临床分离的4种肠杆菌科细菌共148株,用法国生物梅里埃公司VITEK-2全自动细菌鉴定仪进行菌株鉴定和药敏试验,用qnr特异性基因引物进行聚合酶链反应(PCR)扩增和基因型的测序分析,并通过网上GenBank进行比对以确定编码酶基因的类型。结果对喹诺酮类耐药的50株大肠埃希菌检出qnrA1株(2.0%)、qnrB5株(10.0%)、qnrS3株(6.0%),有1株同时携带qnrB、qnrS;30株肺炎克雷伯菌检出qnrA1株(3.3%)、qnrB8株(26.7%)、qnrS10株(33.3%),有3株同时携带qnrB、qnrS;18株阴沟肠杆菌检出qnrA13株(72.2%)、qnrB5株(27.8%)、qnrS4株(22.2%),有3株同时携带qnrA、qnrS,3株同时携带qnrA、qnrB;50株鲍氏不动杆菌未检出qnr基因;携带qnr基因肠杆菌科细菌对氨苄西林/舒巴坦、氨曲南、头孢他啶、头孢曲松、头孢吡肟、磺胺甲噁唑/甲氧苄啶的耐药率均>70.0%,呈现出多药耐药现象。结论医院临床分离4种对喹诺酮类药物耐药的肠杆菌中,除鲍氏不动杆菌未检出qnr基因,其余3种均检出qnrA、qnrB、qnrS基因,以阴沟肠杆菌检出率最高,其次为肺炎克雷伯菌;携带qnr基因肠杆菌科呈现出多药耐药现象;医院在抗菌药物选择压力下,存在质粒介导喹诺酮类耐药基因qnr的流行。  相似文献   

7.
目的了解1株产ESBLs、AmpC酶大肠埃希菌的耐药机制。方法采用纸片扩散法检测1株大肠埃希菌对19种抗菌药物的敏感性,采用聚合酶链反应(PCR)检测6种耐药基因:qnrA、qnrB、qnrC、qnrS、qepA、aac(6′)-Ⅰb,并对qnrB、aac(6′)-Ⅰb基因测序后进行BLAST比对分析。结果该菌株除对碳青霉烯类、酶抑制剂复合抗菌药物类敏感外,对其余药物均耐药;PCR发现该菌株同时携带qnrB和aac(6′)-Ⅰb,经测序并分别与已在美国国立信息中心登录的DQ303921(qnrB4)和EF375621[aac(6′)-Ⅰb-suzhou]型比对,同源性均>99.0%。结论该菌株多药耐药的机制与产ESBLs、AmpC酶及携带qnrB4和aac(6′)-Ⅰb基因有关;该研究是第一篇从1株产ESBLs、AmpC酶大肠埃希菌中检出同时携带qnrB4和aac(6′)-Ⅰb-suzhou型基因的报道。  相似文献   

8.
多药耐药肺炎克雷伯菌喹诺酮类耐药相关基因研究   总被引:8,自引:7,他引:1  
目的 了解多药耐药肺炎克雷伯菌(MDRKP)喹诺酮类耐药机制.方法 对一组25株MDRKP进行了染色体介导和质粒介导的耐药相关基因进行检测和分析.结果 25株中,有19种存在gyrA基因突变(76.0%);9株存在aac(6′)-Ⅰ b-Cr(36.0%);2株存在qnrA1基因(8.0%)、2株存在qnrB基因(qnrB4-like)(8.0%)、3株存在qnrS1基因(12.0%);25株均存在mdfA基因,未检出qepA基因.结论 在MDRKP中,gyrA基因突变是喹诺酮类耐药的主要原因.  相似文献   

9.
目的调查临床分离大肠埃希菌的耐药特征及质粒介导喹诺酮耐药(PMQR)基因流行状况。方法收集本院住院患者分离的大肠埃希菌191株,经VITEK 2全自动鉴定药敏仪进行鉴定和药敏分析,PCR检测PMQR基因qnrA、qnrB、qnrC、qnrD、qnrS、aac(6′)-Ib-cr、oqxA、oqxB、qepA。接合试验分析PMQR基因的转移性。结果 191株菌株对美洛培南和亚胺培南均敏感。对阿米卡星、奈替米星、阿莫西林/克拉维酸、哌拉西林/他唑巴坦和头孢西丁耐药率均低于30%。环丙沙星耐药率为64.4%,PMQR基因检出率为37.7%,123株环丙沙星耐药株中qnrA阳性26.0%、qnrB阳性4.9%、qnrS阳性1.6%、aac(6′)-Ib-cr阳性43.1%、oqxA阳性8.9%、qepA阳性4.9%,未检出到qnrC、qnrD和oqxB。其中40株(32.5%)只检测到单一基因,其余32株(26.0%)检测到2种或2种以上PMQR基因。接合试验证明43株细菌携带的PMQR基因可转移。结论本院分离大肠埃希菌耐药较严重且呈多药耐药,对环丙沙星耐药较高,PMQR基因以qnr和aac(6′)-Ib-cr为主。  相似文献   

10.
质粒介导喹诺酮类耐药(Plasmid-Mediated Quinolone Resistance,PMQR)基因自qnr于1998年在肺炎克雷伯菌中被发现起,目前有3种机制,分别由qnr、aac(6')Ib-cr、qepA 和oqxAB编码,介导喹诺酮靶位保护、药物修饰和药物外排.目前已有5种qnr基因被发现,分别为qnrA、qnrB、qnrS、qnrC、qnrD.  相似文献   

11.
目的 研究临床分离铜绿假单胞菌的耐药性和质粒介导铜绿假单胞菌对环丙沙星耐药的分子机制.方法 采用VITEK-2型全自动微生物检测系统鉴定细菌,用K-B法测定铜绿假单胞菌对24种常用抗菌药物的药敏率,用聚合酶链反应检测喹诺酮类耐药基因,包括qnrA、qnrB、qnrC、qnrD、qnrS、qepA和aac (6') -Ib-cr.结果 423株铜绿假单胞菌对环丙沙星和左氧氟沙星的耐药率均为23.2%,对第一、三代头孢菌素类药物的耐药率>49.2%(除头孢他啶为22.7%),对氨基糖苷类药物庆大霉素、妥布霉素、阿米卡星的耐药率分别为17.5%、17.5%和13.0%,对青霉素类药物的耐药率>40.4%(除哌拉西林为26.2%),对含β-内酰胺酶抑制剂复合物的耐药率差异较大,哌拉西林/他唑巴坦为17.0%,而氨苄西林/舒巴坦为98.6%;对碳青霉烯类药物亚胺培南和美罗培南的耐药率分别为24.6%和26.0%;127株耐环丙沙星铜绿假单胞菌的耐药性明显升高,对左氧氟沙星的耐药率为86.6%,对第三代头孢菌素的耐药率上升至>61.4%,对第四代头孢菌素头孢吡肟的耐药率由20.3%上升至62.2%,对含p内酰胺酶抑制剂复合物的耐药率从17.0%上升至>49.6%,对氨基糖苷类药物庆大霉素、妥布霉素的耐药率上升至>64.6%,对阿米卡星的耐药率由13.0%上升至48.8%;耐环丙沙星铜绿假单胞菌中未检出qnrS基因和qnrC基因,qnrA、qnrB、qnrD、qepA和aac( 6')-Ib-cr的阳性率分别为31.2%、87.5%、15.6%、10.9%、39.1%.结论 临床分离的耐环丙沙星铜绿假单胞菌携带qnrA、qnrB、qnrD、qepA和aac(6')-Ib-cr基因,未检出qnrS、qnrC基因;qnr、qepA和aac (6') -Ib-cr基因是质粒介导的铜绿假单胞菌耐环丙沙星的主要机制.  相似文献   

12.
Few studies have been performed in Puerto Rico concerning the antimicrobial resistance pattern of clinically significant Gram-negative bacilli. The antimicrobial resistance patterns of 5,590 Gram-negative bacteria obtained from three Community-Private Hospitals (CPH) and three University-Affiliated Hospitals (UAH) were evaluated utilizing the institutions' antimicrobial susceptibility reports for the year 2000. The objectives of this study were: to retrospectively evaluate the reported in vitro resistance of clinical isolates of E. coli, K. pneumoniae, E. cloacae, S. marcescens, P. aeruginosa and A. baumannii to selected standard antibiotics and to compare the antimicrobial resistance patterns between Community-Private (CPH) and University Affiliated hospitals (UAH). E. coli was the most common Gram-negative enteric bacilli in both CPH and UAH. In UAH, E. coli demonstrated a statistically significant higher resistance to the selected beta lactams and amikacin antibiotics but not to ciprofloxacin or gentamicin. For K. pneumoniae, the antimicrobial resistant pattern showed that UAH isolates were significantly more resistant to the tested antibiotics with the exception of ceftriaxone. In CPH, E. cloacae isolates were significantly more resistant to piperacillin-tazobactam, ciprofloxacin and gentamicin, while in UAH this organism was more resistant to amikacin. In UAH, S. marcescens isolates demonstrated a statistically significant higher resistance to all tested antibiotics with the exception of imipenem, which was similar in both hospitals group. Pseudomonas aeruginosa demonstrated a statistically significant higher resistance in UAH to all selected antibiotics with the exception of ciprofloxacin and gentamicin, which was similar in both hospitals group. Acinetobacter baumannii was the most resistant organisms in both hospitals group. UAH isolates were significantly more resistant than CPH isolates for all tested antibiotics. When compare with other large-scale antimicrobial resistance studies, the present study results suggest an apparent higher resistance in the Puerto Rican isolates. The high numbers of antimicrobial resistant Gram-negative bacilli in our study strongly suggest multiple mechanisms of antimicrobial resistance including the presence of extended spectrum and chromosomally derepressed beta-lactamases.  相似文献   

13.
目的了解重症监护病房(ICU)分离的耐碳青霉烯类肺炎克雷伯菌的药敏结果及同源性。方法对2014年4—5月某院ICU患者和环境分离的11株耐碳青霉烯类肺炎克雷伯菌进行药敏试验,以及采用随机扩增多态性DNA(RAPD)扩增法进行同源性分析。结果 11株肺炎克雷伯菌8株分离自患者,3株分离自环境,标本分布以痰为主(6株,占54.55%)。药敏试验结果显示:10株(90.91%)对环丙沙星耐药;11株对复方磺胺甲口恶唑均敏感,对亚胺培南均为中介,对其余抗菌药物耐药率均为100%。11株肺炎克雷伯菌均有3个条带,可以分为2型:Ⅰ型10株(1~5号、7~11号菌株),Ⅱ型1株(6号菌株)。结论医院ICU肺炎克雷伯菌耐药严重,ICU患者和环境分离的耐碳青霉烯类肺炎克雷伯菌为同一克隆株。加强ICU环境清洁、消毒及监测,有利于减少和及时预警多重耐药菌,降低医院感染。  相似文献   

14.
目的:研究铜绿假单胞菌对喹诺酮类药物耐药的分子机制,为临床抗感染治疗提供依据。方法:用PCR法检测染色体介导的喹诺酮类耐药基因gyrA、gyrB、parC、parE和质粒介导的喹诺酮类耐药基因qn-rA、qnrB、qnrC、qnrD、qnrS、qepA、aac(6’)-Ib-cr、oqxA和oqxB,并对gyrA和parC阳性结果进行测序分析。结果:98株耐环丙沙星的铜绿假单胞菌中未检出parE、qnrC和qnrS基因。gyrA、gyrB和parC的阳性率分别为96.9%、87.8%和75.5%。测序证实84株菌(85.7%)发生gyrA或parC基因突变。90株菌(91.8%)携带质粒介导的耐药基因,qnrA、qnrB、qnrD、qepA、aac(6’)-Ib-cr、oqxA和oqxB的阳性率分别为31.6%、86.7%、15.3%、11.2%、53.1%、8.2%和26.5%,其中qnrB和aac(6’)-Ib-cr具有高携带率。结论:染色体介导的喹诺酮类耐药基因突变以及质粒携带qnr、qepA、aac(6’)-Ib-cr和oqxAB耐药基因是铜绿假单胞菌耐喹诺酮类药物的主要机制。首次在铜绿假单胞菌中发现qnrB基因和qnrD基因。  相似文献   

15.
目的了解肺炎克雷伯菌对氨基糖苷类抗生素的敏感性及16S rRNA甲基化酶检出情况。方法收集中南大学湘雅医院2009年1-7月非重复肺炎克雷伯菌96株,采用琼脂稀释法对庆大霉素、阿米卡星、妥布霉素的最低抑菌浓度(MIC)进行检测;聚合酶链反应(PCR)扩增16S rRNA甲基化酶基因armA、rmtA、rmtB、rmtC、rmtD和npmA。结果肺炎克雷伯菌对阿米卡星、庆大霉素及妥布霉素的MIC50分别为256 μg/mL、512 μg/mL和512 μg/mL;MIC90均为>512 μg/mL;耐药率分别为21.88%、63.54%、41.67%。68株(70.83%)菌至少对1种药物耐药,21株(21.88%)菌对3种药物均耐药。22株(22.92%)菌armA基因扩增阳性,未扩增到rmtA、rmtB、rmtC、rmtD和npmA基因;22株armA阳性菌株中,17株(77.27%)对3种氨基糖苷类抗生素均耐药。armA阳性株与armA(FJ410928.1)基因序列同源性为100%。结论携带armA型16S rRNA甲基化酶基因是肺炎克雷伯菌对氨基糖苷类药物高水平耐药的主要机制之一。  相似文献   

16.
Twenty-two gentamicin-resistant urinary isolates of Escherichia coli and five gentamicin-resistant urinary isolates of Klebsiella pneumoniae from a Dublin hospital were examined for resistance to the veterinary aminoglycoside antibiotic apramycin. Five isolates of E. coli and one isolate of K. pneumoniae were found to be resistant. The apramycin-resistant isolates, which were also resistant to the veterinary anthelmintic agent hygromycin B, hybridized with a DNA probe for the gene encoding the enzyme 3-N-aminoglycoside acetyltransferase type IV (AAC(3)IV). Resistance to apramycin and hygromycin B was co-transferable in four of the five isolates of E. coli and the isolate of K. pneumoniae. In one isolate of E. coli apramycin resistance was not transferable. On the basis of their restriction enzyme digestion profiles and the antimicrobial resistance traits encoded, the transferable plasmids encoding resistance to apramycin and hygromycin B comprised three distinct types. Genetic linkage between the gene encoding AAC(3)IV and genes encoding resistance to ampicillin and either tetracycline or trimethoprim, means that the relatively widespread use of these antimicrobial agents provides a selective pressure for the persistence of resistance to apramycin and gentamicin even in the absence of bacterial exposure to aminoglycosides.  相似文献   

17.
目的了解安徽省宿州地区临床分离的耐甲氧西林溶血葡萄球菌(MRSH)耐药性、耐药基因携带状况及诱导型克林霉素耐药的发生率。方法采用ATB STAPH5药敏试验板微量肉汤法对42株MRSH进行16种抗菌药物敏感性测定;聚合酶链反应(PCR)法检测MRSH中mecA、qacA/B/C、qacA、ermA/B/C、ermB、TetM耐药基因;D 试验检测诱导型克林霉素耐药表型。结果42株MRSH对万古霉素、呋喃妥因100%敏感,对利福平、米诺环素、奎奴普丁/达福普汀、替考拉宁的敏感率>90%;而对庆大霉素、诺氟沙星、左氧氟沙星的耐药率>70%,对青霉素、苯唑西林、红霉素耐药率为100.00%。mecA、qacA/B/C、qacA、ermA/B/C、ermB、TetM基因阳性率分别为100.00%(42株)、64.29%(27株)、59.52%(25株)、40.48%(17株)、28.57%(12株)、9.52%(4株)。D 试验阳性13株,诱导性耐药占30.95%。结论安徽宿州地区分离的MRSH呈多重耐药性,临床治疗应根据药敏试验结果合理选用抗菌药物。  相似文献   

18.
The World Health Organization has implemented a surveillance program for antimicrobial resistance that is known as WHONET. In Argentina the program was developed through a network of 23 public and private hospitals that participate in national and international quality-control programs. Between January 1995 and December 1996, the antimicrobial susceptibility of 16,073 consecutive clinical isolates was determined, using the recommended standards of the National Committee for Clinical Laboratory Standards of the United States of America. More than half of the Escherichia coli urinary isolates were resistant to ampicillin and more than 30% to trimethoprim/sulfamethoxazole (SXT). When the percentage of resistant isolates from outpatients (OPs) was compared to that observed in hospitalized patients (HPs), a marked difference in antimicrobial activity was noted in the case of gentamicin (2% from OPs resistant vs. 8% from HPs resistant), norfloxacin (2% vs. 6%), and third-generation cephalosporins (7% vs. 15%). Of the Klebsiella pneumoniae isolates recovered from blood cultures, 71% and 60% showed resistance to third-generation cephalosporins and to gentamicin, respectively. The overall rate of oxacillin resistance in Staphylococcus aureus was 39%. Around half of the Enterococcus spp. isolates showed high resistance to aminoglycosides, but resistance to glycopeptides was not found. In Argentina, ampicillin and SXT were not suitable for treating diarrhea. Shigella flexneri had a higher number of isolates resistant to both of those drugs (87% and 74%, respectively) than Sh. sonnei did (47% and 71%, respectively). About 40% of the Salmonella spp. isolated in pediatric hospitals were resistant to third-generation cephalosporins. When microorganisms causing bacterial meningitis were examined, Streptococcus pneumoniae showed a resistance rate of 18% to penicillin and Haemophilus influenzae a resistance rate of 19% to ampicillin. These rates are within the intermediate range reported for other countries of the Americas and for Europe.  相似文献   

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